The invention relates to construction machinery, as well as a pivoting device.
Such construction machinery is known, for instance, from U.S. Pat. No. 4,029,165. In such construction machinery, the machine frame is supported by a chassis with several wheels or crawler track units that are coupled with the machine frame via lifting columns. The lower part of the lifting column is extendable in order to raise the machine frame to a pre-determined plane. Each lifting column can be adjusted in height individually or together with other lifting columns. The machine frame shows a width that is suitable for transport on a transport vehicle. In longitudinal direction, the machine frame shows a length that is a multiple of the width. As used herein, when it is said that one structure “shows” a certain feature, it is meant that the structure includes that feature.
In the known construction machine, the swivel support of each crawler track unit is mounted coaxially below one lifting column, with a slewing ring being arranged at the crawler track unit that enables steering of the crawler track unit by means of a steering cylinder which supports itself at the machine frame. Several articulated brackets are provided at the slewing ring which make it possible, by way of remounting the steering cylinder to other articulated brackets, to swivel a crawler track unit from a transport position parallel to the longitudinal direction of the machine frame to a working position transverse to the longitudinal direction in several work steps.
In transport position, the construction machine is capable of being driven from a transport vehicle and of being steered, whereas in working position, the machine is capable of bridging a carriageway width of up to, for instance, 18 m depending on the length of the machine frame.
Of disadvantage in this design are the great installation effort required on all crawler track units and the risk of accident and injury during the installation work.
The installation effort is caused by the fact that the steering cylinder is suitable for enabling a swivelling angle of approx. 45° only. Additional articulated brackets must therefore be provided at the slewing ring in order to enable the steering cylinder to be remounted for further swivelling of the crawler track unit and to enable it to be coupled to a different articulated bracket. In the process, it causes difficulty to bring the piston rod of the steering cylinder into an aligned position with a different articulated bracket at the slewing ring for the purpose of articulated locking.
In a different embodiment without additional articulated brackets, a coupling rod enables the steering function of the crawler track unit in transport position to be transmitted to the crawler track unit arranged on the other side of the machine frame.